Merge branch 'master' into dev-pep484

.gitlab-ci.yml

@@ -61,6 +61,11 @@ docs:
   - pip install Sphinx
   script:
   - python setup.py docs
+  artifacts:
+    paths:
+    - public
+  only:
+  - tags
 
 # This deploy job uses a simple deploy flow to Heroku, other providers, e.g. AWS Elastic Beanstalk
 # are supported too: https://github.com/travis-ci/dpl
@@ -68,5 +73,5 @@ docs:
 #  type: deploy
 #  environment: production
 #  script:
-#  - python setup.py 
+#  - python setup.py
 #  - dpl --provider=heroku --app=$HEROKU_APP_NAME --api-key=$HEROKU_PRODUCTION_KEY

CHANGELOG.rst

@@ -8,7 +8,7 @@ Changelog
 ------------------
 * remove not implemented argument `show_url` of `dump_cassandra_data()`
 * write tests that are independent of access to the IBPT network
-* move directory structure to new one (cassandra->src/cassandra) to complete `PyScaffold` structure
+* move directory structure to new one (`cassandra`->`src/cassandra`) to complete `PyScaffold` structure
 * Upgrade PyScaffold to be compatible with new setuptools versions
 
 0.7.1 (2017-10-31)

CONTRIBUTING.rst

@@ -5,7 +5,7 @@
 Contributing
 ============
 
-Contributions are welcome, and they are greatly appreciated! 
+Contributions are welcome, and they are greatly appreciated!
 
 You can contribute in many ways:
 
@@ -15,7 +15,7 @@ Types of Contributions
 Report Bugs
 ~~~~~~~~~~~
 
-Report bugs at https://git.scc.kit.edu/las/py/cassandra/issues.
+Report bugs at https://git.scc.kit.edu/las-software/15-3-DataProcessing/cassandra/issues.
 
 If you are reporting a bug, please include:
 
@@ -40,14 +40,16 @@ Write Documentation
 ~~~~~~~~~~~~~~~~~~~
 
 cassandra could always use more documentation, whether as part of the
-official cassandra docs, in docstrings.
+official cassandra docs, in docstrings or the examples.
 
 The documentation is generated automatically using `Sphinx docs`_ with the napoleon extension.
-So please write your docstrings following `Google's docstring convention`_. 
+So please write your docstrings following `Google's docstring convention`_.
 
 .. _`Sphinx docs`: http://www.sphinx-doc.org
 .. _`Google's docstring convention`: http://www.sphinx-doc.org/en/stable/ext/example_google.html?highlight=napoleon
 
+Since Sphinx does not handle Python 2's type annotations (`PEP 484 <https://www.python.org/dev/peps/pep-0484/#suggested-syntax-for-python-2-7-and-straddling-code>`_) well, it is still necessary to write the type in the docstring.
+
 Write Tests
 ~~~~~~~~~~~
 
@@ -56,7 +58,7 @@ Try to increase the test coverage by writing tests.
 Submit Feedback
 ~~~~~~~~~~~~~~~
 
-The best way to send feedback is to file an issue at https://git.scc.kit.edu/las/py/cassandra/issues.
+The best way to send feedback is to file an issue at https://git.scc.kit.edu/las-software/15-3-DataProcessing/cassandra/issues.
 
 If you are proposing a feature:
 
@@ -75,12 +77,13 @@ Ready to contribute? Here's how to set up `cassandra` for local development.
 
     $ git clone git@git.scc.kit.edu/YOURNAME/cassandra.git
 
-3. Install your local copy into a virtualenv. Assuming you have virtualenvwrapper installed, this is how you set up your fork for local development::
+3. Install your local copy into a virtualenv or venv, which ships with Python 3::
 
-    $ mkvirtualenv cassandra
     $ cd cassandra/
+    $ python3 -m venv .venv
+    $ source .venv/bin/activate
     $ python setup.py develop
-    $ python -m pip install -r test-requirements.txt
+    $ python -m pip install -r test-requirements.txt -r requirements.txt
 
 4. Create a branch for local development::
 
@@ -96,10 +99,12 @@ Ready to contribute? Here's how to set up `cassandra` for local development.
 
    To get flake8 and tox, just pip install them into your virtualenv.
 
+   Change things marked by the pre-commit-hooks if there are some.
+
 6. Check for upstream updates::
 
-    $ git remote add upstream https://git.scc.kit.edu/las/py/cassandra.git
-    $ git fetch upstream 
+    $ git remote add upstream https://git.scc.kit.edu/las-software/15-3-DataProcessing/cassandra.git
+    $ git fetch upstream
     $ git checkout master
     $ git merge upstream/master
     $ git checkout name-of-your-bugfix-or-feature
@@ -121,14 +126,15 @@ Before you submit a pull request, check that it meets these guidelines:
 1. The pull request should include tests.
 2. If the pull request adds functionality, the docs should be updated. Put
    your new functionality into a function with a docstring, and add the
-   feature to the list in README.rst.
-3. The pull request should work for Python 2.7, 3.4, 3.5 and 3.6, and for possibly PyPy and other versions. 
+   feature to the list in README.rst and CHANGELOG.rst.
+3. The pull request should work for Python 2.7, 3.4, 3.5 and 3.6, and possibly PyPy and other versions.
 
-Tips
-----
+..
+    Tips
+    ----
 
-Try to increase the test coverage. You can check the coverage by running
+    Try to increase the test coverage. You can check the coverage by running
 
-    $ make cov
+        $ make cov
 
-and opening the `htmlcov/index.html` file.
+    and opening the `htmlcov/index.html` file.

README.rst

@@ -4,7 +4,7 @@ Cassandra
 
 Cassandra_ — ANKAs aktuelles (Stand 2016) Archivierungsdatenbanksystem. Es existiert eine JSON-API, die aus dem ANKA-Netz (las-bernhard.anka.kit.edu) verfügbar ist.
 
-EPICS — ANKAs neuestes Kontrollsystem (Stand 2016), in welchem u. a. der CLIC-Dämpfungswiggler integriert ist. Aus diesem wird Cassandra befüllt. Für weitere Informationen siehe z. B. Arbeitsgruppenvortrag von Walter Werner, ANKA-Confluence, sowie die `offizielle EPICS Seite`_ 
+EPICS — ANKAs neuestes Kontrollsystem (Stand 2016), in welchem u. a. der CLIC-Dämpfungswiggler integriert ist. Aus diesem wird Cassandra befüllt. Für weitere Informationen siehe z. B. Arbeitsgruppenvortrag von Walter Werner, ANKA-Confluence, sowie die `offizielle EPICS Seite`_
 
 PV — EPICS-Variable, die hier abgefragt werden kann.
 
@@ -23,7 +23,7 @@ Installation
 
 ::
 
-    python -m pip install "git+ssh://git@git.scc.kit.edu:/las/py/cassandra.git#egg=cassandra"
+    python -m pip install "git+ssh://git@git.scc.kit.edu:/las-software/15-3-DataProcessing/cassandra.git#egg=cassandra"
 
 
 Script
@@ -34,7 +34,7 @@ Das Script `./fetch.py` läd Daten eines PV und plottet sie
 
 cassandra.py Python-Klasse zum abstrahieren von Cassandra (basiert auf dem fetch.py-Skript)
 
-Unter `bin` sind ein beispielhaftes Skript zur Verwendung der Cassandra-Klasse (`plot_two.py`). 
+Unter `bin` sind ein beispielhaftes Skript zur Verwendung der Cassandra-Klasse (`plot_two.py`).
 Auch wird das Kommandozeilen-Programm zum anzeigen von gemittelten Werten aus der Cassandra-Datenbank:`get_mean_values.py` installiert.
 
 JSON-Dateien
@@ -60,14 +60,16 @@ The docu is generated using `Sphinx <https://sphinx-doc.org>`_, is written in `R
 
 You can compile the docu either by using the setup.py::
 
-    $ python setup.py docs
+    $ python setup.py build_sphinx
 
-or by hand by running::
-    
-    $ cd docs && sphinx-apidoc -f -o ./_source ../cassandra
+In detail this dose something similar to the following steps.
+Run the sphinx-apidoc::
+
+    $ cd docs && sphinx-apidoc -f -o ./_source ../src/cassandra
+
+Include the filenames (ls `*.rst >> index.rst`) into `index.rst` at a appropriate place and add three spaces before them (e.\,g. care about the indention!)
+and finally by run::
 
-including filenames (ls `*.rst >> index.rst`) into `index.rst` at a apropiate place and add three spaces before them (e.\,g. care about the indention!)
-and finally by running::
     $ make latexpdf
     $ okular _build/latex/cassandra.pdf
 
@@ -78,14 +80,17 @@ or::
 
 To setup your own documentation if you're not using PyScaffold you need to
 install Sphinx and napoleon::
+
     $ pip install Sphinx
     $ pip install sphinxcontrib-napoleon
 
-create the docs directory and initialize the project::
+Create the docs directory and initialize the project::
 
     $ mkdir docs
     $ cd docs
-    $ sphinx-quickstart (project path: ../cassandra, source-build seperated)
+    $ sphinx-quickstart (project path: ../src/cassandra, source-build seperated)
 
-configure it by editing `source/conf.py` and adding `shpinx.ext.napoleon` to the list of extensions and
+Configure its configuration by editing `source/conf.py` and adding `shpinx.ext.napoleon` to the list of extensions and
  uncommenting `import sys` and `import os` and modifying `abspath('../..')`.
+
+Create some required directories `mkdir _source _static`.

docs/changelog.rst

+.. _changes:
+.. include:: ../CHANGELOG.rst

docs/examples.rst

+.. _examples:
+
+========
+Examples
+========
+
+Here are some examples how you can use the Classes as well as how you can use the script.
+
+If I write Cassandra I am speaking of this Python class, if I write cassanda I am referencing to the package and if I am writing Cassandra-DB I am speaking of the `Apache Cassandra <https://cassandra.apache.org/>`_ instance at KARA.
+
+Scripts
+-------
+
+Classes
+-------
+
+Let's say we want to have the time a specific fill started, then we can ask the Cassandra-DB to provide us the fill numbers for the time range of the beginning of the data logging (let's say 1st Jan, 2005) till today.
+
+This could be done with the following function that uses the Cassanda's context manager (with statement) to also care about exceptions.
+
+The context manager needs at least the start and end date and time for which it should ask for data and the process variable (PV) name.
+So in our case this could something like :obj:`datetime.datetime(2005, 1, 1, 0, 0, 1)` as `start` and `datetime.datetime.now()` as `end`. The PV name is `'A:SR:OperationStatus:01:FillNumber'`.
+
+Putting it together this gives us
+
+.. code:: Python
+
+    from cassandra.cassandra import Cassandra
+    import datetime
+
+    with Cassandra(start=datetime.datetime(2005, 1, 1, 0, 0, 1),
+                   end=datetime.datetime.now(),
+                   pv="A:SR:OperationStatus:01:FillNumber") as data:
+        times, fills = data
+
+Now the `times` list has got all the datetimes of the fill numbers that are in the `fills` list as integers.
+Since we did not provide any number for the optional argument `count` the number of entries is not known and we need not to have one entry for each fill.
+
+As it is not always convenient to provide :obj:`datetime.datetime` objects, you can also write the `start` and `end` date as strings in some common formats, like ISO-8601 or CSS-exports' format or the format used by the THz group.
+
+For an explanation of the `count` argument see the documentation of Cassandra-DB's web-interface in the Confluence wiki.
+The also optional argument `directory` does not make sense for the context manager, and is there for creating objects.
+
+Now we can create another simple example that utilises the above mentioned string format, the count argument and uses the helper class :class:`cassandra.cassandra.Pvs`.
+
+* The starting time, which we will provide as the string `"2005/01/01 00:00:01"`,
+* the end time, which we may give as a :obj:`datetime.datetime` object,
+* the PV name for which we can use the `fill` of the `Pvs.pv` dictionary, and
+* in this case we want to limit the counts to `1`, because the frequency of the fills is very low.
+
+We end up with a code that might look like:
+
+
+.. code:: Python
+
+    #!/usr/bin/env python
+    # -*- coding: utf-8 -*-
+
+    from cassandra import Cassandra, Pvs
+    import datetime
+
+
+    def fill_to_time(fill: int) -> datetime.datetime:
+        """Return datetime of the KARA fill
+
+        Args:
+            fill: Fill number
+
+        Returns:
+            Fill time
+        """
+        now_str = datetime.strftime(datetime.now(), "%Y/%m/%d %H:%M:%S")
+        with Cassandra("2005/01/01 00:00:01", now_str, Pvs.pv["fill"], 1) as data:
+            times, fills = data
+            return times[fills.index(fill)]
+
+    fill_to_time(6000)
+
+
+The `data` object we get from the handler is a :obj:`tuple` of two :obj:`list` s that contain the date stamps as :obj:`datetime.datetime` returned from Cassandra and the corresponding data. In our case the latter are the fill numbers.

docs/index.rst

@@ -7,10 +7,11 @@ Contents
 .. toctree::
    :maxdepth: 2
 
+   Examples <examples>
+   Module Reference <api/cassandra>
+   Changelog <changelog>
    License <license>
    Authors <authors>
-   Changelog <changelog>
-   Module Reference <api/modules>
    Contributing <contributing>
 
 

setup.cfg

@@ -54,6 +54,7 @@ norecursedirs =
 
 [aliases]
 release = sdist bdist_wheel upload
+docs = build_sphinx
 
 [bdist_wheel]
 # Use this option if your package is pure-python
@@ -62,6 +63,7 @@ universal = 1
 [build_sphinx]
 source_dir = docs
 build_dir = docs/_build
+fresh-env = true
 
 [devpi:upload]
 # Options for the devpi: PyPI server and packaging tool

setup.py

@@ -9,6 +9,7 @@
 """
 
 import sys
+
 from setuptools import setup
 
 # Add here console scripts and other entry points in ini-style format
@@ -18,14 +19,16 @@ entry_points = """
 # For example:
 # fibonacci = cassandra.skeleton:run
 """
+if sys.version_info <= (3,):
+    requires = ['pyscaffold==2.5.10']
+else:
+    requires = ['pyscaffold>=3.0a0,<3.1a0']
 
 
 def setup_package():
     needs_sphinx = {'build_sphinx', 'upload_docs'}.intersection(sys.argv)
     sphinx = ['sphinx'] if needs_sphinx else []
-    setup(setup_requires=['pyscaffold>=3.0.2a0,<3.1a0'] + sphinx,
-          entry_points=entry_points,
-          use_pyscaffold=True)
+    setup(setup_requires=requires + sphinx, entry_points=entry_points, use_pyscaffold=True)
 
 
 if __name__ == "__main__":

src/cassandra/__init__.py

 # -*- coding: utf-8 -*-
 """ A module to handle typical tasks concerning ANKA's ``Cassandra``.
-Read data from ANKA's ``Cassandra`` and exported data exported by ``Control System Studio``'s ``Data Browser``
+Read data from KARA's ``Cassandra`` database and exported data exported by ``Control System Studio``'s ``Data Browser``
 
 .. moduleauthor:: Julian Gethmann <atb@gethmann.org>
+
+To read data from CSS exports you need the :func:`css_read.load_css_data`.
+
+To read data from the cassandra-db you either need to use the class
+:class:`cassandra.Cassandra` probably with its context manager.
+Or you can use the :func:`pd.pvs2pd` function to export the data directly
+to a pandas :obj:`pandas.DataFrame`.
+
+If you don't know a specific, but common, process variable name changces are
+high you might find it in the :obj:`cassandra.Pvs.pv` dictionary.
+
+Finally there are some helper functions, like time conversions, in the :class:`cassandra.CassandraHelper`
+class.
 """
 from pkg_resources import get_distribution, DistributionNotFound
 

src/cassandra/cassandra.py

@@ -25,9 +25,9 @@ __copyright__ = "Julian Gethmann"
 __license__ = "mit"
 __all__ = ["Cassandra", "CassandraHelper", "Pvs"]
 
-try:  # Py2
+try:  # Py3
     from urllib.error import URLError
-except ImportError:  # Py3
+except ImportError:  # Py2
     from urllib2 import URLError
 
 
@@ -217,16 +217,14 @@ class CassandraHelper(object):
             except ValueError:
                 pass
             except TypeError:
-                raise TypeError(
-                    "Time ({}) must either be a `datetime.datetime` or a string"
-                    " as described in the docstring and not a {}.".format(
-                        time_string, type(time_string).__name__))
+                raise TypeError("Time ({}) must either be a `datetime.datetime` or a string"
+                                " as described in the docstring and not a {}.".format(
+                                    time_string, type(time_string).__name__))
 
         if not ret:
-            raise ValueError(
-                "`time_string` must not be of the form `{}` and type {}! "
-                "See docstring for possible forms.".format(
-                    time_string, type(time_string).__name__))
+            raise ValueError("`time_string` must not be of the form `{}` and type {}! "
+                             "See docstring for possible forms.".format(
+                                 time_string, type(time_string).__name__))
         else:
             return ret
 
@@ -270,8 +268,8 @@ class CassandraHelper(object):
                     values.append(entry["value"])
         # if entry["status"] == "OK" or entry["severity"]["level"] == "OK"]
         timestamps = [
-            datetime.datetime.fromtimestamp(entry["time"] / 1e9)
-            for entry in json_data if entry["severity"]["level"] == "OK"
+            datetime.datetime.fromtimestamp(entry["time"] / 1e9) for entry in json_data
+            if entry["severity"]["level"] == "OK"
         ]
 
         dataset = namedtuple("dataset", ["timestamps", "values"])
@@ -370,11 +368,7 @@ class Cassandra(object):
             bool: True if the connection is ok, False if an error occurred
         """
         try:
-            tmp = Cassandra(
-                "2017-07-07T08:08:08",
-                "2017-07-07T08:08:08",
-                Pvs.pv["energy"],
-                count=1)
+            tmp = Cassandra("2017-07-07T08:08:08", "2017-07-07T08:08:08", Pvs.pv["energy"], count=1)
             tmp.timeout = 1
             tmp._download_cassandra_data()
         except (TimeoutError, URLError):
@@ -413,7 +407,7 @@ class Cassandra(object):
         })
 
     def _download_cassandra_data(self):
-        # type: (...) -> List[str]
+        # type: (Cassandra) -> List[str]
         """Return Cassandra's JSON as an JSON object. """
         url = self.gen_url()
         try:
@@ -431,9 +425,7 @@ class Cassandra(object):
                 except URLError:
                     pass
             else:
-                raise URLError(
-                    "Request had a timeout. Maybe you're not inside the ANKA-LAN"
-                )
+                raise URLError("Request had a timeout. Maybe you're not inside the ANKA-LAN")
         elif CassandraHelper.PY2:
             import urllib2 as request
             for err_count in range(self.RETRIES):
@@ -449,13 +441,12 @@ class Cassandra(object):
                     "Request had a timeout. Maybe you're not inside the IBPT-CN-LAN or provided a wrong PV name"
                 )
         else:
-            raise NotImplementedError(
-                "Not implemented for other versions than 2 or 3!")
+            raise NotImplementedError("Not implemented for other versions than 2 or 3!")
 
         return json_data
 
     def dump_cassandra_data(self):
-        # type: (...) -> str
+        # type: (Cassandra) -> str
         """Dump the JSON file to a file named like the PV and time that is returned
 
         Dump a JSON file fetched from the Cassandra `host` and return its name.
@@ -472,6 +463,7 @@ class Cassandra(object):
         return path.abspath(self.json_file)
 
     def get_json_local(self):
+        # type: (Cassandra) -> Tuple[List[datetime.datetime], List[Union[List[float], float]]]
         """ Return timestamps and values for given Cassandra object and copy JSON file if neccessary."""
         if not path.isfile(self.json_file) or path.getsize(self.json_file) <= 2:
             self.dump_cassandra_data()

src/cassandra/pd.py

@@ -3,8 +3,10 @@
    :Authors: Julian Gethmann
    :Contact: atb@gethmann.org
    :Date: 2017-09-15
+
    .. versionadded:: 0.5.5
    .. versionchanged:: 0.7.0
+
 """
 from datetime import datetime
 from typing import Iterable, List, Optional, Tuple  # flake8: noqa
@@ -18,16 +20,16 @@ def pvs2pd(
         start,  # type: datetime.datetime
         end,  # type: datetime.datetime
         pv_names,  # type: Iterable[str]
-        count=None,  # type: Optional[int]
-        upsample=None,  # type: Optional[str]
-        save_local=False,  # type: Optional[bool]
-):  # type (...) -> pd.DataFrame
-    # Optional[int], Optional[str], Optional[bool]) -> pd.DataFrame
-    """Return a `pd.DataFrame` with data for all `pv_names` and `time` as index
+        count=None,  # type: int
+        upsample=None,  # type: str
+        save_local=False,  # type: bool
+):
+    # type (...) -> pd.DataFrame
+    """Return a :obj:`pandas.DataFrame` with data for all `pv_names` and `time` as index
 
     Missing data points are filled with the last value (like in CSS).
     The sampling rate is not corrected to be constant (like in CSS).
-    The `pd.DataFrame` starts with the start date and takes the last saved data
+    The `pandas.DataFrame` starts with the start date and takes the last saved data
     for it and ends with the end date and also takes the filled data.
 
     .. note::
@@ -51,7 +53,7 @@ def pvs2pd(
             are saved locally in the same directory.
 
     Returns:
-        pd.DataFrame: "time" as index and `pv_names` as columns.
+        pandas.DataFrame: "time" as index and `pv_names` as columns.
 
     Examples:
         >>> from datetime import datetime
@@ -71,22 +73,19 @@ def pvs2pd(
         pv = Pvs.pv[pv_name] if ":" not in pv_name else pv_name
         if save_local:
             cas = Cassandra(start, end, pv=pv, count=None, directory=".")
-            data = cas.get_json_local(
-            )  # type: Tuple[List[datetime.datetime], List[float]]
+            data = cas.get_json_local()  # type: Tuple[List[datetime.datetime], List[float]]
             collected_data = collected_data.join(
                 pd.DataFrame({
                     "time": data[0],
                     pv_name: data[1]
-                }).set_index("time"),
-                how="outer")
+                }).set_index("time"), how="outer")
         else:
             with Cassandra(start, end, pv=pv) as cas:
                 collected_data = collected_data.join(
                     pd.DataFrame({
                         "time": cas[0],
                         pv_name: cas[1]
-                    }).set_index("time"),
-                    how="outer")
+                    }).set_index("time"), how="outer")
     collected_data = collected_data.ffill()
     collected_data = collected_data[collected_data.first_valid_index():]
     # if start in collected_data.index:

src/cassandra/tools.py

@@ -4,13 +4,12 @@
    :Authors: Julian Gethmann
    :Contact: phd@gethmann.org
 
-   .. lastupdated:: 2017-01-25
-
    Return the mean and standard deviation for the PVs in the given time range.
 """
 import argparse
 import logging
 from math import sqrt
+from typing import Optional, Tuple, Union  # flake8: noqa
 
 from .cassandra import Cassandra, Pvs
 
@@ -19,11 +18,12 @@ logging.getLogger('cassandra.tools').addHandler(logging.NullHandler())
 
 
 def _get_mean_values(
-        start_time="2016/04/07 13:30:00",
-        end_time="2016/04/07 14:00:00",
-        pvs=("q1", "q2"),
-        output_format="full",
+        start_time="2016/04/07 13:30:00",  # type: Optional[Union[datetime.datetime,str]]
+        end_time="2016/04/07 14:00:00",  # type: Optional[Union[datetime.datetime,str]]
+        pvs=("q1", "q2"),  # type: Tuple[str, str, ...]
+        output_format="full",  # type: str
 ):
+    # type: (...) -> None
     """
     .. versionchanged:: 0.3.0
     """
@@ -43,37 +43,29 @@ def _get_mean_values(
         "str": "{val}",
     }
     for pv in pvs:
-        with Cassandra(
-                start_time, end_time, Pvs.pv.get(pv, pv), count,
-                directory="/tmp/") as obj:
+        with Cassandra(start_time, end_time, Pvs.pv.get(pv, pv), count, directory="/tmp/") as obj:
             if "str" in output_format:
                 _logger.info("Raw string for PV: {}".format(pv))
                 try:
                     print(obj[1][0])
                 except KeyError:
-                    raise KeyError(
-                        "No %s as output_format available!" % output_format)
+                    raise KeyError("No %s as output_format available!" % output_format)
             else:
                 _logger.info("Values for PV: {}".format(pv))
                 try:
                     mean = sum(obj[1]) / len(obj[1])
-                    std = sqrt(
-                        sum([(xi - mean)**2
-                             for xi in obj[1]]) / (len(obj[1]) - 1))
-                    print(output_str[output_format].format(
-                        name=pv, val=mean, std=std))
+                    std = sqrt(sum([(xi - mean)**2 for xi in obj[1]]) / (len(obj[1]) - 1))
+                    print(output_str[output_format].format(name=pv, val=mean, std=std))
                 except ValueError:
-                    raise ValueError(
-                        "Probably too short time to get enough points")
+                    raise ValueError("Probably too short time to get enough points")
                 except KeyError:
-                    raise KeyError(
-                        "No %s as output_format available!" % output_format)
+                    raise KeyError("No %s as output_format available!" % output_format)
 
 
 def get_mean_values():
-    parser = argparse.ArgumentParser(
-        description="Return the mean value "
-        "and standard deviation for the PVs in the given time range.")
+    # type: () -> None
+    parser = argparse.ArgumentParser(description="Return the mean value "
+                                     "and standard deviation for the PVs in the given time range.")
     parser.add_argument(
         "--start",
         "-s",
@@ -99,12 +91,7 @@ def get_mean_values():
         required=False,
         help="short name of the PV (see PVs class from cassandra module)")
     parser.add_argument(
-        "--rawpv",
-        dest="rawpvs",
-        nargs="?",
-        type=str,
-        required=False,
-        help="full name of *one* PV")
+        "--rawpv", dest="rawpvs", nargs="?", type=str, required=False, help="full name of *one* PV")
     parser.add_argument(
         "--raw",
         "-r",

test-requirements.txt

@@ -4,4 +4,5 @@
 pandas
 pytest
 pytest-cov
+sphinx
 tox

tests/test_cassandra.py

@@ -8,9 +8,6 @@
 import datetime
 import json
 import os
-import pathlib
-from urllib import error, request
-from urllib.error import URLError
 
 import cassandra
 import pytest
@@ -19,6 +16,18 @@ from cassandra.cassandra import Cassandra
 # from cassandra.cassandra import *
 from .conftest import request_openurl
 
+try:
+    import pathlib
+except ImportError:
+    pass
+
+try:  # Py3
+    from urllib import request
+    from urllib.error import URLError
+except ImportError:  # Py2
+    from urllib2 import URLError
+    import urllib2 as request
+
 
 @pytest.mark.usefixtures("cleandir", "setup_")
 class TestCassandraClass(object):
@@ -32,7 +41,9 @@ class TestCassandraClass(object):
         assert cas2.count is None
         assert cas2.start_time == start
         assert cas2.end_time == end
-        assert pathlib.Path(cas2.directory).absolute() == pathlib.Path.cwd()
+